Confronting spin flavor solutions of the solar neutrino problem with current and future solar neutrino data

Abstract

A global analysis of spin flavor precession (SFP) solutions to the solar neutrino problem is given, taking into account the impact of the full set of latest solar neutrino data, including the recent SNO data and the 1496-day Super-Kamiokande data. These are characterized by three effective parameters: $\ensuremath{\Delta}{m}_{\mathrm{SOL}}^{2}\ensuremath{\equiv}\ensuremath{\Delta}{m}^{2},$ the neutrino mixing angle ${\ensuremath{\theta}}_{\mathrm{SOL}}\ensuremath{\equiv}\ensuremath{\theta},$ and the magnetic field parameter $\ensuremath{\mu}{B}_{\ensuremath{\perp}}.$ For the last we adopt a self-consistent magnetohydrodynamics field profile in the convective zone and identify an optimum ${B}_{\ensuremath{\perp}}\ensuremath{\sim}80\mathrm{kG}$ strength for $\ensuremath{\mu}{=10}^{\ensuremath{-}11}{\ensuremath{\mu}}_{B}.$ We find that no low mass (LOW) quasivacuum or vacuum solutions are present at $3\ensuremath{\sigma}.$ In addition to the standard large mixing angle (LMA) oscillation solution, there are two SFP solutions, in the resonant (RSFP) and nonresonant (NRSFP) regimes. These two SFP solutions have a goodness of fit of 84% (RSFP) and 83% (NRSFP), slightly better than the LMA oscillation solution (78%). We discuss the role of solar antineutrino searches in the fit and present a table of best-fit parameters and ${\ensuremath{\chi}}_{\mathrm{min}}^{2}$ values. Should the KamLAND experiment confirm the LMA solution, the SFP solutions may at best be present at a subleading level, leading to a constraint on $\ensuremath{\mu}{B}_{\ensuremath{\perp}}.$ In the event the LMA is not the solution realized in nature, then experiments such as Borexino can help in distinguishing the LMA solution from the NRSFP solution and the simplest RSFP solution with no mixing.